With high demand in high-speed and high-volume information transmission for both homes and institutions, the telecommunication industry has introduced more sophisticated optical devices to satisfy such demand. To continuously improve bandwidth and speed, a next-generation passive optical network 2 (“NGPON2”) has been introduced recently as a new telecommunications network standard for a passive optical network (“PON”). A feature of NGPON2 is that it is able to operate within the existing PON (passive optical network) fiber structures. NGPON2, for example, operates at different wavelengths than the existing PON (i.e., GPON or XGPON). NGPON2 typically has its own associated optical line terminals (“OLTs”) and optical network units (“ONUs”) and operates alongside to other PON OLTs and ONUs. The signals from NGPON2 OLTs are multiplexed by wavelength multiplexer (“WM”) before being combined with other signals using the Co-existence Element
Optical communication networks typically offer high-speed voice, video, and data transmission to/from users and/or institutions. For example, PON generally includes fiber to the node/neighborhood (“FTTN”), fiber to the curb (“FTTC”), fiber to the building (“FTTB”), fiber to the home (“FTTH”), fiber to the premises (“FTTP”), or other edge location to which a fiber network extends. To transmit optical signals from a source to a destination over a PON, for example, the optical signals travel through multiple passive optical components such as fiber cables, optical splitters and attenuators that make up the optical distribution network (“ODN”).
NGPON2 generally employs a range of wavelength division multiplexed (“WDM”) channels/wavelengths to operate within the time and wavelength division multiplexed (“TWDM”) PON environment. For example, a conventional NGPON2 can have up to eight (8) WDM channels which carry a set of discreet wavelengths generated by multiple optical transceivers or lasers. The set of discreet wavelengths are usually multiplexed onto a single fiber (i.e., SSMF—Single, Single Mode Fiber). To reduce the complexity and cost associated with the discreet implementation, a photonic integrated circuit (“PIC”) technology has been developed. For example, multiple channels can be integrated into a single PIC.
A problem, however, associated with a conventional PIC is that manufacturing yield for producing such PICs can be low. For example, a PIC is typically discarded when one of the channels or lasers is defective thereby the failure generally renders the entire device or PIC useless. Another problem associated with conventional PIC is that a good PIC device deployed in the field may stop functioning when one of the channels or lasers within PIC stops working. For example, if a channel in a PIC fails or degrades, the entire PIC device has to be replaced and discarded.
A conventional approach to mitigate a channel failure within an optical device is to switch device port(s) from a port connected to a failed channel to another port connected to a working channel. A drawback associated with port switching is that it negatively impacts resources since each device has limited number of ports. Another drawback associated with the port switching is that it adds additional traffic to a working port while the port connected to a bad laser is, for example, is in a failed state. If a port has multiple channels, to replace the device on the port, all channels have to be switched including the working one(s) to other channels.